Comparing geometric discord and negativity for bipartite states

Publication date: Available online 18 September 2019Source: Physics Letters AAuthor(s): Priyabrata Bag, Santanu Dey, Hiroyuki OsakaAbstractThe geometric discord D of a state is a measure of the quantumness of the state and the negativity N is a measure of the entanglement of a state. It was proved by D. Girolami and G. Adesso that for states on C2⊗C2, the geometric discord is always greater than or equal to the square of the negativity and conjectured that this holds in general. S. Rana and P. Parashar showed that this relation does not hold for all states on C2⊗Cn for n>2. We provide several analytic families of states on C2⊗C3 violating this relation. Certain upper and lower bounds for N2−D are obtained for states on Cm⊗Cn for any m,n∈N.

Source: Physics Letters A - September 19, 2019 Category: Physics Source Type: research